Acetylcholine-induced coronary spasm in patients with unobstructed coronary arteries is associated with elevated concentrations of soluble CD40 ligand and high-sensitivity C-reactive protein

OBJECTIVESTo assess whether epicardial and microvascular coronary artery spasm in response to acetylcholine (ACH) is associated with markers of inflammation, platelet stimulation, and endothelial activation in patients with angina and unobstructed coronary arteries. BACKGROUNDPatients with angina pectoris despite angiographically normal coronary arteries represent a diagnostic and therapeutic challenge. Both impaired coronary microvascular dilatory responses as well as diffuse distal epicardial and microvascular coronary artery spasm have been described as possible pathogenic mechanisms. Although inflammation has been proposed to play a pathogenic role in angina, an association between ACH-induced coronary vasospasm and inflammation in Caucasians has not been reported previously in this context. PATIENTS AND METHODSWe assessed 62 consecutive patients (26 men, age 60±10 years) with chest pain despite angiographically unobstructed coronary arteries (